On Fri, Nov 2, 2012 at 4:09 PM, Robert Sanderson <azaroth42@gmail.com>wrote:
>
> To try and express a concrete example of Antoine's concern, if I
> understand correctly...
>
> A client is trying to render an annotation that uses OA and OAX. With
> just the link to OA Core, you can't determine which version of OAX is being
> used, as it is likely not in step with OA.
> Now add in DC, Prov and two community specific extensions and that little
> modelVersion really doesn't do us any good at all.
>
That is a problem indeed.
>
> Maybe we do drop it under the not-really-useful-to-anyone test?
>
> Or include a timestamp and leave it up to other systems to determine the
> version of all of the namespaces that was in use at that time?
>
I am not sure that would work. Applications come and go. I would prefer
having a serialization that is more explicit - includes the version of the
model - and survives the application.
Plus who knows, maybe some applications will be able to consume/produce
multiple versions at one point so the timestamp would not help.
Paolo
On Fri, Nov 2, 2012 at 12:23 PM, Paolo Ciccarese
<paolo.ciccarese@gmail.com>wrote:
>
>
> On Fri, Nov 2, 2012 at 2:08 PM, Antoine Isaac <aisaac@few.vu.nl> wrote:
>
>> Hi Rob,
>>
>> Thanks for the explanation. Indeed it's a tricky issue, and it's maybe
>> good to work on it after the dust has settled a bit on the others. In fact
>> the fact that we're discussing a lot does not create a mindset that helps
>> conceiving that OA will be much more stable than now, one day ;-)
>> And of course we'll need some time to look at available receipes around
>> us.
>>
>> Trying to react at some points:
>>
>> - namespace: indeed it's imperative to use only one namespace for each
>> vocabulary. The DC solution I've mentioned is no exception. As I
>> understood, it, the time-stamped URI are in fact rather version "numbers",
>> not property URIs that would replace the canonical one in RDF graphs.
>>
>> - "using the URI of the core spec". Are you meaning the option that Bob
>> and Paolo mentioned, i.e. have
>> http://www.openannotation.org/spec/core/20120509.html as the value for
>> oa:modelVersion ? Indeed even if I fully accepted using oa:modelVersion,
>> I'd still have doubts about that one. ".html" indicates a document, not a
>> version of an ontology, which in my mind is a bit more abstract. I'd rather
>> use "http://www.openannotation.org/spec/core/20120509". It looks like
>> splitting hair, but already avoids a lot of ambiguity. Of coruse then best
>> practice would recommend that if looks up the URI you can serve the
>> corresponding version of the spec, i.e.,
>> http://www.openannotation.org/spec/core/20120509.html and, say
>> http://www.openannotation.org/spec/core/20120509.rdf
>>
>
> I could work with "http://www.openannotation.org/spec/core/20120509" . I
> was using the .html as, right now, it resolves... for human consumption at
> least.
>
>
>
>>
>> - the point on serializedAt, serializedBy is very interesting. Indeed if
>> the property had been "oa:serializationModel" then I might have been less
>> anxious about it. When properties look like humble "short-cuts" of some
>> more complex paths. I'm less enclined to think that you wanted to solve the
>> vocabulary versioning problem within the entire graph... And it seems like
>> it would be less vulnerable to corner-case but real situations, e.g. if a
>> same annotation happens to be serialized using different models at
>> different times.
>> (but that being said, I still don't think it's optimal ;-) )
>>
>
> I could go wither way. I would not mind to change "modelVersion' to
> "oa:serializationModel" or similar as it is specifying better that is a
> serialization thing and not a property of the Annotation itself.
>
> Paolo
>
>
>
>>
>> Antoine
>>
>>
>>
>>> Hi Antoine,
>>>
>>> There's actually very little about modelVersion. Basically, we wanted at
>>> least an identifier to allow systems to determine whether they have
>>> encountered a draft, stable, or subsequent version of the model. The
>>> easiest way to do that was to have a pointer from the annotation to some
>>> resource that identifies the model version.
>>>
>>> We discussed this issue at the first f2f meeting with Dan Brickley,
>>> regarding FOAF and namespaces. He strongly recommended to only ever have
>>> one namespace, and hence we didn't use that as the identifier.
>>> Another suggestion was to use a datetime for the model (which would need
>>> to be different from the annotation's timestamp as clients may create new
>>> annotations after a revision to the model). This would allow the use of
>>> Memento, for example, to retrieve the schema or documentation that was in
>>> use for that point in time, rather than the current schema/docs.
>>>
>>> The reasoning for putting it on the annotation is the same as the
>>> serializedAt, serializedBy, and mimetype going on the annotation.
>>>
>>> Overall, it's a tricky problem! We didn't want to make it very
>>> heavyweight, but thought it should be addressed.
>>> And of course we agree that the model should be as stable as possible,
>>> and only the most important changes should break backwards compatibility to
>>> the stable spec.
>>>
>>> We do foresee the OAX schema changing more rapidly than the Core. This
>>> issue of versions and maintenance is the main reason for the split. Given
>>> that, however, using the URI of the Core spec doesn't seem sufficiently
>>> granular?
>>>
>>> Rob
>>>
>>>
>>> On Fri, Nov 2, 2012 at 7:45 AM, Antoine Isaac <aisaac@few.vu.nl <mailto:
>>> aisaac@few.vu.nl>> wrote:
>>>
>>> Hi,
>>>
>>> Sorry in advance for yet another long trolling, but I wanted to
>>> discuss for a while.
>>>
>>> Is there somewhere a documentation on how this versioning info ended
>>> up modelled this way?
>>> I understand the requirement, but I have doubts whether it should be
>>> handled like this in the core of the OA model.
>>>
>>>
>>> (1) It should be quite a minor requirement.
>>>
>>> The requirement is crucial in theory, but it's best tackled by not
>>> raising the issue that motivate it in the first place. The best practice is
>>> really to keep a vocabulary as stable and backwards-compatible as possible!
>>>
>>> Of course it's difficult when the model is still being worked on.
>>> But once an "official"/"stable" version is released, any change that is not
>>> backwards-compatible should be strongly discouraged--at least when it would
>>> impact a lot of existing data.
>>>
>>>
>>> (2) It's questionable whether a domain model like OA should support
>>> vocabulary-level versioning.
>>>
>>> The problem of data and model versioning applies across the board,
>>> for every data that is created. If you want to apply it to OA, you may want
>>> to have it for the other vocabularies used with it: DC, etc.... If all of
>>> them included a specific versioning mechanism, interoperability would just
>>> vanish.
>>> In general one would count on specific representation feature in the
>>> data model (like named graphs in RDF) or a very specific "meta-domain"
>>> vocabulary like PROV or the Resource Map part of OAI-ORE [1]. Possibly in
>>> combination...
>>>
>>> The awkwardness of trying to address at the OA level shows in the
>>> issues raised by attaching the version data to the Annotation resource. Why
>>> should it be considered a property of the Annotation? And how to interpret
>>> it when consuming data from different contexts? (E.g., if two annotations
>>> "with different models" share a same target with its Selector.)
>>>
>>> On a different level, the current solution may fall short when
>>> elements remain stable across versions. How should one decide if two
>>> statements with a "same" property are directly interoperable or if they
>>> shouldn't be mixed? Will the vocabulary include some time-stamped resources
>>> for each element, as in DC [2]?
>>>
>>>
>>> I'm ready to accept that there are alternative views, or even
>>> scenarios I would have overlooked. But meanwhile I am truly convinced that
>>> the current situation is sending quite bad signals...
>>>
>>>
>>> If we really want to say something about versioning data then I'd
>>> rather:
>>>
>>> - keep track of the version information at the general vocabulary
>>> level (OWL ontology files published at different URIs with version info in
>>> it like owl:versionIRI [3])
>>>
>>> - recommend the use a meta-level scheme (PROV, OAI-ORE, Named
>>> Graphs, whatever) for linking data graphs or "records" to these versioned
>>> ontologies
>>>
>>> And then leave to the people who don't trust OA to be stable the
>>> burden of exploiting that in the way they see fit.
>>> All others will be alright never have been presented this data
>>> (especially if is represented in a inappropriate way).
>>>
>>> Antoine
>>>
>>> [1] http://www.openarchives.org/__ore/1.0/primer <
>>> http://www.openarchives.org/ore/1.0/primer>
>>> [2] Cf.
>>> http://dublincore.org/usage/__terms/history/#__tableOfContents-003 <
>>> http://dublincore.org/usage/terms/history/#tableOfContents-003> . Of
>>> course not many really use it outside of the DC documentation...
>>> [3]
>>> http://www.w3.org/TR/owl2-__syntax/#Versioning_of_OWL_2___Ontologies <
>>> http://www.w3.org/TR/owl2-syntax/#Versioning_of_OWL_2_Ontologies> .
>>> This could be also handled with http://www.w3.org/TR/swbp-__vocab-pub/ <
>>> http://www.w3.org/TR/swbp-vocab-pub/>, possibly with Memento-like http
>>> redirections.
>>>
>>>
>>>
>>>
>>> +1
>>>
>>> I am currently using that URL as the model version.
>>>
>>> Paolo
>>>
>>>
>>> On Thu, Nov 1, 2012 at 4:31 PM, Bob Morris <morris.bob@gmail.com<mailto:
>>> morris.bob@gmail.com> <mailto:morris.bob@gmail.com <mailto:
>>> morris.bob@gmail.com>>> wrote:
>>>
>>> Is there, or could there be declared, a suitable value of
>>> oa:modelVersion corresponding to
>>> http://www.openannotation.org/__spec/core/20120509.html <
>>> http://www.openannotation.org/spec/core/20120509.html>
>>>
>>> (how about, dare I say it, use that as the value)?
>>>
>>> In our annotation generation and consumption components, RuleML
>>> rules, SPARQL queries from forms, ...., we are starting to move
>>> from
>>> AO to OA. Embedding an oa:modelVersion in our annotations would
>>> help
>>> us keep track of exactly where we stand, especially as OA
>>> evolves and
>>> we find we need to make changes. We have several parts of our
>>> system
>>> that all need to be using the same annotation vocabulary. I
>>> guess we
>>> don't need a standardized oa:modelVersion, but we are also
>>> beginning
>>> to think about the scope of our collaboration with others
>>> working on
>>> the same kinds of biodiversity data annotation using OA. The more
>>> agreement on modelVersion the less confusion...
>>>
>>> Bob
>>>
>>>
>>> --
>>> Robert A. Morris
>>>
>>> Emeritus Professor of Computer Science
>>> UMASS-Boston
>>> 100 Morrissey Blvd
>>> Boston, MA 02125-3390
>>>
>>> IT Staff
>>> Filtered Push Project
>>> Harvard University Herbaria
>>> Harvard University
>>>
>>> email: morris.bob@gmail.com <mailto:morris.bob@gmail.com>
>>> <mailto:morris.bob@gmail.com <mailto:morris.bob@gmail.com>>
>>>
>>> web: http://efg.cs.umb.edu/
>>> web: http://etaxonomy.org/mw/__FilteredPush <
>>> http://etaxonomy.org/mw/FilteredPush>
>>>
>>> http://www.cs.umb.edu/~ram <http://www.cs.umb.edu/%7Eram>
>>>
>>> ===
>>> The content of this communication is made entirely on my
>>> own behalf and in no way should be deemed to express
>>> official positions of The University of Massachusetts at Boston
>>> or
>>> Harvard University.
>>>
>>>
>>>
>>>
>>> --
>>> Dr. Paolo Ciccarese
>>> http://www.paolociccarese.__info/ <
>>> http://www.paolociccarese.info/>
>>>
>>> Biomedical Informatics Research & Development
>>> Instructor of Neurology at Harvard Medical School
>>> Assistant in Neuroscience at Mass General Hospital
>>> +1-857-366-1524 <tel:%2B1-857-366-1524> (mobile) +1-617-768-8744<tel:%2B1-617-768-8744> (office)
>>>
>>>
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>
--
Dr. Paolo Ciccarese
http://www.paolociccarese.info/
Biomedical Informatics Research & Development
Instructor of Neurology at Harvard Medical School
Assistant in Neuroscience at Mass General Hospital
+1-857-366-1524 (mobile) +1-617-768-8744 (office)
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